Originally Posted by JBrunner
sorry for being late here in your thread. I've overlooked it in December.
you think right: MF slide projection is the bomb!!
The most impressive picture quality photography has to offer. It is absolutely a league of its own.
I am doing slide projection for more than 30 years now, and I will never stop doing it.
Well, as some of you know, were running a small non-profit optical test lab here.
And weve done lots of detailed tests concerning slide film (colour and BW) and slide projection, as well as evaluating the performance of beamers.
Tests results from our team:
We have tested all the films with a relative low object contrast of 1:4 (two stops). Lenses were Nikkor AI-S 1,8/50 (long barrel version) and Zeiss ZF 2/50 at f5,6 (and some others as well).
Both lenses have the same performance in the center at f4 and f5,6, but the Zeiss is generally better at the corners and at f2.
Some test results from our resolution tests (Nikon F6, MLU, MC-30, 1/250s, focus bracketing, Zeiss ZF 2/50, f5,6, Nikkor AI-S 1,8/50, object contrast 1:4; Berlebach Report 3032.
The first resolution value represents the number of clearly separated lines, the second one the resolution limit where still a contrast difference can be seen.
Resolution is dependant on the object contrast of the detail you have focused at: with higher object contrast, you would get higher resolution than our test results [see the tests published by Zeiss], and lower object contrast would result in lower resolution values):
Fuji Velvia 50: 110 125 Lp/mm
Fuji Sensia 100: 120 135 Lp/mm
Fuji Provia 100F: 120 135 Lp/mm
Fuji Astia 100F: 120 135 Lp/mm
Fuji Velvia 100: 125 140 Lp/mm
Fuji Velvia 100F: 125 140 Lp/mm
Kodak E100G: 120 135 Lp/mm
Kodak Elitechrome 100: 120 135 Lp/mm
Fuji Provia 400X: 105 115 Lp/mm
Agfa Copex Rapid; ISO 64/19°; Agfa Scala BW reversal process : 165 180 Lp/mm.
Adox CMS 20 II; ISO 20/14°; Agfa Scala BW reversal process: 230 245 lp/mm
Mamiya 645 Pro TL with Mamiya-Sekor C 2,8/80 N, f5,6; same object contrast of 1:4 = two stops.
Fuji Provia 100F: 115 125 lp/mm
Agfa Copex Rapid, Scala Reversal process: 130 145 lp/mm
Adox CMS 20 II; Scala reversal process: 195 210 lp/mm
And, with excellent projection lenses you can transfer the above listed resolution values with only a minimal (not relevant) loss onto the projection screen!
We've tested several projection lenses, e.g. the Leica Super-Colorplan P2 2,5/90, Zeiss P-Sonnar T 2,5/90, Doctor-Optics / Kindermann 2,4/90 MC-B, Rollei Apogon 2,8/120.
With all these lenses we could transfer the 120 lp/mm of E100G, Elitechrome 100, Provia 100F, Sensia 100, Astia 100F onto the screen!
Same with the 165 lp/mm of Agfa Copex Rapid and the 230 lp/mm of Adox CMS 20 II as BW-Slide (developed in Scala reversal process)!
120 lp/mm in 35mm format: That is an equivalent of 50 Megapixels. You need a 50 MP beamer to get the same detail at this object contrast. The 165 lp/mm of Agfa Copex Rapid are equivalent to 94 MP, for the Adox a 200 MP equivalent would be needed.
Looking at 35mm slide projection with an excellent projection lens, then the quality is even surpassing digital medium format projected with a beamer. Because the imaging chain film + projection is much, much better than the digital imaging chain digital file + beamer. The beamer is the very weak part in this imaging chain and decreases the quality of the file to a big extent. From your 40,50, 60 or 80 MP only 1,2,4 or max 8 MP (most expensive gear) remain as beamer output (and with beamers you also have the problem that the resolution is even 40% less in vertical format).
Concerning colour rendition the current beamers also cannot compete with the much more precise and natural color rendition of the slides.
Therefore in the field of projection we indeed have the situation, that 35mm film is significantly surpassing all digital formats (including medium format) in picture quality.
And of course in costs. 35mm slide projection is dirt cheap in comparison.
And of course with medium format slide projection, using excellent lenses (camera and projection), you can significantly surpass the already outstanding 35mm performance:
Well, the 115 lp/mm of the Sekor 2,8/80 / Provia 100F combination (see above), projected e.g. with the 2,8/120 Apogon with the Rollei 66 dual P:
120 MP on the screen.
155 MP with the Agfa Copex Rapid.
350 MP with the Adox CMS 20 II.
Its incredible what outstanding picture quality medium format slide projection is giving us.
Well, best sex for the eyes
For big enlargements slide projection delivers an unsurpassed quality. And at extremely low costs ( a projected slide on a 2 m x 2 m screen cost me less than one Euro, a print of the same size cost me more than two hundred Euros).